Question

The value of y is directly proportional to the value of x. When = 512, y = 128.

What is the value of y when x = 64?

Answer 1

Explanation:

directly proportional means same

x=y

512=128

64=y

512/64=8

128/8=16

when x=64 then the value of y=16

Answer 2

C

Explanation:

given y is directly proportional to x then the equation relating them is

y = kx ← k is the constant of proportion

to find k use the condition when x = 512, y = 128

128 = 512k ( divide both sides by 512 )

`(128)/(512)` = k , that is k = 0.25

y = 0.25x ← equation of proportion

when x = 64 , then

y = 0.25 × 64 = 16